Liquid seal for floating roofs



July 25, 1950 l. E. BOBERG LIQUID SEAL FOR FLOATING ROOF'S Filed Nov.30, 1945 Patented July 25, 1950 LIQUID SEAL FOR FLOATING BOOFS Irving E.Bobcrg, Chicago, 11]., assignor to Chicfislg firldge & Iron Company, acorporation of Application November 30, 1945, Serial No. 631,812

2 Claims. (01. 220-26) This invention relates to a liquid seal for afloating roof, and more particularly to a seal employing the same, or,substantially the same liquid as that employed in the vessel.

The invention is illustrated in the drawings in which:

Fig. 1 is a plan view partly in section 01 a roof; and

Fig. 2 is a fragmentary sectional elevation taken along the line 2-2 inFig. 1.

The seal is intended for use in a liquid storage 2 vessel in having sidewalls of sheet metal II. The roof 20 is indicated as a pontoon typehaving a bottom 2|, an annular upstanding rim 22, and a top 23 whichslopes downwardly and inwardly to the center of the pontoon.

The seal comprises a flexible sheet of fabric material 24 which issecured at the bottom 01 the rim to an annular flange 25, and at the topto the horizontal arm 01' the angle 21. The vertical arm of the angle issecured to the top 23 and thus forms a liquid filled annular channel.

The space between the rim 22 and the fabric is partially filled bysealing liquid 30 which is preferably the same liquid as that in thestorage vessel. In the case of highly volatile liquids, however, such ashigh test gasoline, the sealing liquid may be of slightly lower vaporpressure. It is not, however, sufficiently diflerent to endangerpollution oi. the tank contents in the event of a seal break. The weightof the liquid causes the fabric to form a slight loop 3i at the bottom.

The fabric is also supported in a loop 32 at the top by suitablesupporting means, such as the pivoted lever 33.

Inasmuch as the distance between the rim 22 and the side wall ll mayvary considerably as the roof rises and falls, due to irregularities intank construction, the amount of liquid required within the seallikewise varies. In order to accommodate excessive liquid and to provideliquid when more is required I maintain one or more reservoirs 40,located on the top of the roof. These reservoirs are suitably connectedas by lines II to the liquid space within the seal. It i preferred tohave a number of connections from the reservoir to the seal. The pipesfor such connections have been indicated at right angles to each other.A plurality of such reservoirs may be provided, if desired, with one ormore connections to each.

The liquid level within the seal is maintained above the normaldisplacement level of the root,

and the amount of liquid within the reservoir 40 is sufllcient tomaintain this excess head of liquid at all times, and under allconditions and positions of the roof.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom.

What I claim as new, and desire to secure by Letters Patent, is:

i. In a liquid storage tank having a floating roof. means for sealingthe space betwen the root and the sides of the tank comprising: anannular flexible sealing member having one edge attached to the upperportion 01' the roof and having the other edge attached to the lowerportion of the roof to form a pocket, said member having a firstintermediate portion extending upwardly from the edge to the side of thetank, a second intermediate portion extending downwardly along thesides, and a third intermediate portion extending upwardly to the otheredge, a hanger in the pocket and pivotally mounted on the roof, saidhanger being in engagement with the underside of the first intermediateportion to support said first intermediate portion in an outwardlyconvexed loop of substantially U-shaped cross section, a sealing liquidpartially filling the pocket, and a reservoir 01' sealing liquid on theroof and connected to the pocket to maintain the head of the sealingliquid in excess 01' the head of the liquid within the tank at allpositions of the roof.

2. A storage vessel as set forth in claim 1 in which the sealing liquidis substantially the same as the liquid within the storage vessel.

IRVING E. BOBERG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,426,998 Leland et al. Aug. 22,1922 2,085,752 Horton et al July 8, 1937 FOREIGN PATENTS Number CountryDate 94,546 Switzerland May 1, 1922 437,158 Germany Nov. 16, 1926695,985 Germany Apr. 25, 1934

